Review of Coordinate and Alignment Lectures

Astronomy 25

1) Which of these are constant and which vary with time/location?

Constant Vary

Celestial sphere -

Celestial horizon -

Celestial equator -

Zenith -

N & S Celestial Poles -

Meridian -

2) It’s best to view an object near the horizon or meridian? __________

3) Will the numbers obtained using the alt/az coordinate system be useful to someone at another place or time? ______

4) Declination is measured pretty much like latitude. (T/F)

5) Right Ascension is measured pretty much like longitude. (T/F)

6) Declination is measured in what units? ___________

7) Right ascension is measured in what units? _____________

8) The “zero-point” for right ascension is the ________ ________.

9) Right ascension increases to the East/West? ________

10) The declination of our zenith is the same as our ____________.

11) The ecliptic is the path of the ________ against the stars.

12) The zodiacal constellations lie along the ____________.

13) How many of them are there? _____

14) The earth’s polar axis traces a circle in the sky every 20,000 years or so because of the earth’s _____________.

15) The earth is tilted _____° to its orbit around the Sun.

16) Why is it hotter in summer than in winter? (Small diagram sufficient.)

17) Fill in the data or check the correct answer, as applicable:

Longest Shortest Date

R.A Dec. Day? Day? of Event

Vernal Equinox

Summer Solstice

Autumnal Equinox

Winter Solstice

18) Between _______° and _______° latitude, the Sun may appear directly overhead.

19) If the earth had no tilt, what would be the result? _________________

20) The most important star in telescope alignment for us is __________.

21) The ____________ mount compensates for earth’s movement most easily.

22) What setting circle will always need adjustment during calibration? ______

23) Polaris is exactly at the North Celestial Pole. (T/F)

24) If you don’t find a desired star in your FOV after moving the telescope to its setting circle coordinates it means your alignment is bad. (T/F)

25) The electric clock drive on our telescope adjusts the (Dec. or R/A) for earth’s movement? ________